Refrigeration system with vortex means



Jan. 12, 1960 BARTLETT, JR 2,920,457

REFRIGERATION SYSTEM WITH VORTEX MEANS Filed March 5, 1958 INVENTORIJAMES L. BARTLETEJR.

U i ed W8 P m REFRIGERATION SYSTEM WITH VORTEX MEANS James L. Bartlett,IL, Rolling Hills, Calif., assignor to The Garrett Corporation, LosAngeles, Calif a corporation of California This invention pertains torefrigeration systems and more particularly to a vapor cyclerefrigeration system which utilizes a vortex tube as a heat exchangemeans for dissipating heat to the surrounding atmosphere.

As is well known, a' conventional vapor cycle refrigeration systemutilizes a compresor to increase the pressure of the gaseous refrigerantwithdrawn from the evaporator. verted to a liquid in a condenser bytransferring heat to the surrounding atmosphere or other coolant, afterwhich the liquid refrigerant is passed through an expansion valve orother throttling or expansion device where it is partly converted to alow temperature gas. The mixture of liquid and gas, at relatively lowtemperature and pressure, then flows through the evaporator where therefrigerant absorbs heat from the medium being cooled, and the heatedrefrigerant, now completely gaseous,'flows from the evaporator back tothe compressor where its pressure is again increased and the cyclerepeated.

The size of the condenser required in the above-described vapor cyclerefrigeration system is dependent, of course, on many variables, such asthe temperature of the atmosphere or other coolant surrounding thecondenser, the refrigerant used and the system pressures. The choice ofrefrigerant as well as the pressures used in the system can be varied tomeet difierent conditions, but the temperature of the surroundingatmosphere or other medium is usually fixed. Thus, in order to furtherdecrease the size of the condenser after the refrigerant and systempressures have been chosen, it would be necessary to increase thetemperature diflerence between the compressed refrigerant and thesurrounding atmosphere or to increase the coolant flow. This is oftennot feasible in the conventional type of vapor cycle system employing acondenser, and thus the size of the condenser can only be reduced to acertain minimum.

This invention would solve the problem of increasing the temperaturedifference between the compressed refrigerant and the surroundingatmosphere by utilizing a vortex tube in place of the condenser normallyemployed in such systems. The vortex tube is preferably of the typehaving a closed end hot tube so that none of the refrigerant is lost tothe surrounding atmosphere. Such a vortex tube is more particularlydescribed and claimed in the co-pending application of Frederick H.Green, Serial No. 171,147, filed June 29, 1950, now Patent No.2,839,898, and entitled Multiple Vortex Tube Generator Cooling Unit.This type of vortex tube operates without loss of fluid and with thetemperature of the fluid flowing in the hot tube above the temperatureof the fluid admitted to the tube. This temperature difierence betweenthe inlet temperature of the gas and the temperature of the gas in thehot tube results in a greater temperature diiferential between thetemperature of the refrigerant and the surrounding coolant, thuspermitting a decrease in the amount of heat exchange surface required.

The compressed refrigerant is then con- 2,920,457 Patented Jan. 12, 1960Accordingly, the principal object of this invention is to provide anovel vapor cycle refrigeration system -which utilizes a vortex tube inplace of the conventional condenser.

A still further object of this invention-is to provide a novel vaporcycle refrigeration system which is very compact and is capable of highefficiency over a wide range of temperature of the coolant employed.

These and further objects and advantages of this invention will be moreeasily understood by those skilled in the art to which it pertains, fromthe following detailed description of a preferred embodiment when ,takenin conjunction with the attached drawing. The drawing shows a schematicarrangement of a vapor cycle refrigeration system embodying theprinciples of this invention.

Referring to the drawing, there is shown a suitable compressor unit 10,in this instance illustrated as being a motor-driven centrifugalcompressor, which compresses the gaseous refrigerantwithdrawn from theevaporator 22. The discharge of the compressorltl is connecied to theinlet 12 of a vortex tube 13 by means of a conduit 11. The vortex tube'13 has a hot tube 14 extending from one end of the inlet 12 and a coldtube or outlet 20 extending from the opposite side of the inlet. Theinlet 12,.of course, should be designed so that the compressed gaseousrefrigerant is caused-to flow in a helical path into the interior of thehot tube 14, andto return out the cold tube 20, as required in operatinga vortex tube of the aforementioned type- The operation of such a vortextube ismore fully. explained in the above-referenced copendingapplication. The extreme end 15 or the hot tube 14 is closed by anydesired means, such as an end cap or the like, in order to prevent theescape of refrigerant from the system. The hot tube 15 may also beprovided with suitable fins 16 in order to increase the surfaceavailable for transferring heat from the refrigerant in the hot tube tothe surrounding atmosphere or other coolant. In some cases it may bedesirable to provide artificial means, such as a fan or pump, not shown,for increasing the flow of coolant over the surface of the hot tube 14.

The cold outlet 20 of the vortex tube is connected, by means of aconduit 21, to the evaporator 22 of the refrigeration system. The lowerend of the cold outlet 20 serves as the liquid receiver for the system,although it may be desirable in some systems to provide a separatereceiver. An expansion valve 23 or other flow restricting means ismounted in the conduit 21 for controlling the expansion of the liquidrefrigerant into a low pressure gas and liquid mixture.

The discharge of the evaporator 22 is connected to the inlet of thecompressor 10 by means of the conduit 25 so that the gaseous refrigerantdischarge from the evaporator may be recompressed by the compressor 10.A small motor-driven pump or fan 24 is shown for circulating the mediumwhich is being refrigerated over the coils of the evaporator 22. Thefan, of course, is unnecessary in many refrigeration systems, such asthose utilized in household refrigerators.

As explained in the above-reference-co-pending application, a vortextube may be operated with the end of the hot tube completely closed, andthe surface of the hot tube will act as a heat exchanger to transfer tothe surrounding coolant heat from the gaseous fluid flowing in a helicalor vortical path in the hot tube.

The temperature of the refrigerant vapor flowing at the inner peripheryof the hot tube will be much higher than its inlet temperature, and thusthe transfer of heat from the compressed gaseous refrigerant to thesurrounding coolant will be improved due to the greater tempera- "ice 3ture difference between the gas and the coolant, thus permitting areduction in the heat transfer area required in order to supply adesired condensing capacity. In addition to decreasing the size of theover-all system, the use of the vortex tube also permits the system tooperate efficiently over a wider range of temperatures of the coolant.

While but one embodiment of this invention has been described in detail,many additional modifications and improvements will occur to thoseskilled in the art within its broad spirit and scope.

I claim:

1. A vapor cycle refrigeration system comprising:

means for increasing the pressure of a refrigerant; a vortex tube; theinlet of said vortex tube being connected to the discharge of saidpressure increasing means; the cold outlet of said vortex tube beingconnected to the evaporator of the refrigeration system; and the outletof said evaporator being connected to the inlet of said pressureincreasing means.

2. A vapor cycle refrigeration system comprising: a compressor means;the discharge of said compressor means being connected to the inlet of avortex tube, said vortex tube having a closed end hot tube, the coldoutlet of said vortex tube being connected to an evaporator; and theoutlet of said evaporator being connected to the inlet of saidcompressor.

3. A vapor cycle refrigeration system comprising: a compressor means forincreasing the pressure of the refrigerant; the discharge of saidcompressor being connected to the inlet of a vortex tube, said vortextube having a closed end hot tube; passage means for connecting the coldoutlet of said vortex tube to an evaporator; flow restricting meansdisposed in said passage means for re- A} stricting the flow therein andthe outlet of said evaporator being connected to the inlet of saidcompressor means.

4. A refrigeration system comprising: compressor means for increasingthe pressure of a gaseous refrigerant; the discharge of said compressorbeing connected to the inlet of a vortex tube, said vortex tube having aclosed end hot tube; cooling means disposed on said hot tube; the coldoutlet of said vortex tube being connected to an evaporator; and saidevaporator being connected to the inlet of said compressor.

5. A refrigeration system comprising: compressor means for increasingthe pressure of a gaseous refrigerant; the discharge of said compressorbeing connected to the inlet of a vortex tube, said vortex tube having aclosed end hot tube; cooling means disposed on said,hot tube; the coldoutlet of said vortex tube being connected to an evaporator; and meansfor controlling the flow from said cold outlet to said evaporator.

6. In a refrigeration system having compressor means for increasing thepressure of a refrigerant, expansion means for said refrigerant, andevaporator means for said refrigerant; condensing means for saidrefrigerant comprising a vortex tube, the inlet of said vortex tubebeing connected to the discharge of said compressor means and the outletof said vortex tube being connected to said expansion means.

References Cited in the file of this patent UNITED STATES PATENTS1,952,281 Ranque Mar. 27, 1934 2,111,904 Schlumbohm Mar. 22, 19382,295,983 Williams Sept. 15, 1942 2,683,972 Atkinson July 20, 19542,790,310 Green Apr. 30, 1957

